A) Plasma B) Gas and dust C) Rock formations D) Liquid water
A) Gamma rays B) Radio waves C) Visible light D) X-rays
A) Microwave heating B) Ionization imbalance C) Radiative torque alignment D) Heat conduction
A) H II regions B) Molecular clouds C) Reflection nebulae D) Supernova remnants
A) Helium B) Oxygen C) Hydrogen D) Carbon
A) Diamonds B) Gold C) Platinum D) Silicates
A) Carbon monoxide (CO) B) Polycyclic aromatic hydrocarbons (PAHs) C) Carbon dioxide (CO2) D) Methane (CH4)
A) Red B) Yellow C) Blue D) Green
A) H II region B) Supernova remnant C) Dark nebula D) Reflection nebula
A) 10 quadrillion (1016) molecules/m3 B) 1 trillion (1012) molecules/m3 C) 1 billion (109) molecules/m3 D) 100 ions/m3
A) Coronal gas B) Photodissociation region C) Warm ionized medium D) Cold dense phase
A) 50% B) 1% C) 5% D) 10%
A) Neutron stars B) White dwarfs C) Red giants D) OB stars
A) < 300 K B) ~ 106 K C) ~ 104 K D) O(105 K)
A) ~ 1012 molecules/m3 B) ~ 1016 molecules/m3 C) ~ 1025 molecules/m3 D) ~ 100 ions/m3
A) Photodissociation region B) Warm intercloud phase C) Very hot gas (T ~ 106 K) D) Cold dense phase
A) Pressure varies significantly across different regions. B) The phases are roughly in pressure balance over most of the Galactic disk. C) Thermal pressure is more important than magnetic fields. D) All phases have equal density.
A) René Descartes B) Francis Bacon C) William Huggins D) Edward Barnard
A) Ly-α photon from hydrogen B) 21-cm line of H I C) Spectral lines from CO D) Forbidden lines of O III
A) Stellar nucleosynthesis during stellar evolution. B) Primordial nucleosynthesis C) Interstellar dust D) Cosmic rays
A) They decrease the density of the ISM. B) They create cold neutral medium. C) They convert surrounding gas into the warm ionized phase, increasing temperature. D) They reduce the number of hydrogen atoms.
A) Inverse Compton scattering B) Bremsstrahlung radiation C) Photon emission from de-excitation D) Synchrotron radiation
A) Dipole radiation B) 21-cm line emission C) Millimetre wavelength lines D) Far infrared quasi-blackbody emission
A) H2 (molecular hydrogen) B) N II C) O III D) CO (carbon monoxide)
A) Bremsstrahlung cooling B) Synchrotron radiation C) Inverse Compton scattering D) Collision with atomic nuclei
A) It prevents star formation in spiral arms. B) It has no effect on the ISM. C) It influences their dynamics and structure. D) It compresses all ISM into a thin disk.
A) It becomes entirely in the coronal phase. B) It only contains cold gas. C) It is profoundly modified by the central supermassive black hole. D) It remains unchanged from the rest of the galaxy.
A) 21-cm line emission B) Synchrotron radiation C) Far infrared quasi-blackbody emission D) Millimetre wavelength lines
A) Synchrotron radiation B) Quasi-blackbody emission C) Bremsstrahlung radiation D) Inverse Compton scattering
A) 2020 B) 2040 C) 2025 D) 2030
A) Scattering B) Absorption lines C) Reddening D) Emission lines
A) Only hydrogen and helium molecules. B) Carbon monoxide. C) Buckminsterfullerene (C60) or 'buckyballs'. D) Simple hydrocarbons.
A) Edward Barnard B) Mary Lea Heger C) Slipher D) Victor Hess
A) Refraction B) Telescope lens C) Spectroscopy D) Photography
A) Fine structure cooling B) Inverse Compton scattering C) Synchrotron radiation D) Bremsstrahlung radiation
A) They contribute to the heating of the warm neutral medium. B) They reduce the number of photons with energy below the Lyman limit. C) They increase the density of molecular clouds. D) They cool down the ionized gas.
A) Lyman-alpha transition B) Brackett-alpha transition C) Balmer-alpha transition D) Paschen-alpha transition
A) Synchrotron radiation B) Bremsstrahlung radiation C) Far infrared quasi-blackbody emission D) Dipole radiation from spinning nanometre-sized grains
A) Synchrotron radiation B) Bremsstrahlung radiation C) Gamma-ray photons D) Infrared emission
A) 30,000 parsecs B) 500 parsecs C) 100 parsecs (300 light years) D) 10,000 parsecs
A) 500 km/s B) 200 km/s C) 50 km/s D) 1000 km/s |